Tuesday, 31 July 2018

Various Wireless Network Standards

The good news about wireless networks is that there are multiple flavours, each with their own advantages and disadvantages. The bad news is that trying to decide which version to get when buying a system can get confusing.The good news is that very rapidly, the prices of the wireless systems and fast-paced development is creating dual- and tri-mode systems on the market that can speak many different wireless languages.

Here are the three major wireless systems on the market today:

»IEEE 802.11a: Wireless networks that use the Institute for Electrical and Electronics Engineers (IEEE) 802.11a standard use the 5 GHz radio frequency band. Equipment of this type is among the fastest wireless networking equipment widely available to consumers.

»IEEE 802.11b: Home wireless networks that use the IEEE 802.11b standard use the 2.4 GHz radio band. This is the most popular standard in terms of numbers of installed networks and numbers of users.

»IEEE 802.11g: The last and newest member of the 802.11 wireless family, IEEE 802.11g is coming to market as this book goes to press. In fact, only a draft of the IEEE 802.11g specification has been approved with the finalized specs due by mid-2003. In many ways, 802.11g offers the best of both worlds — backward compatibility with IEEE 802.11b networks (it,too, operates over the 2.4 GHz radio frequency band) and the speed of 802.11a networks

»802.11n:In late 2009, IEEE released a newer and faster standard called 802.11n. The 802.11n system is backward compatible, which means that older 802.11b and 802.11g systems can work just fine on an 802.11n network. 802.11n systems can also support the 5 GHz frequencies. A lot of new technology in 802.11n extends the range of the network also the speed of 802.11n is five times faster than 802.11g or 802.11a networks.

Note: - Equipment supporting all four of these finalized standards — 802.11a, 802.11b, 802.11g, and 802.11n — can carry the Wi-Fi logo that’s licensed for use by the Wi-Fi Alliance trade group based on equipment that passes interoperability testing.

Comparing the standards

The differences between these four standards fall into five main categories:

»Data speed: 802.11a and 802.11g networks are almost five times faster than the original 802.11b networks and 802.11n is five times faster still. Any current Wi-Fi gear will be faster than the Internet connection into your house.

»Price:802.11g networking gear has been on the market since the mid-2000s accordingly, the price for this gear is low .The new 802.11n adapters can cost about twice as much.

»Radio signal range: 802.11a wireless networks tend to have a shorter maximum signal range than 802.11b and g networks whereas 802.11n can have two times more range than802.11g since it uses a new technology called MIMO (Multiple-Input & Multiple-Output).

»Radio signal interference: The radio frequency band used by both 802.11b and 802.11g equipment is used also by other home devices, such as microwave ovens and portable telephones, resulting sometimes in network problems caused by radio signal interference.

»Interoperability:Since 802.11a and 802.11b/g use different frequency bands, they can’t communicate over the same radio frequency band. Whereas 802.11g equipment is designed to be backward compatible with 802.11b equipment both operating on the same frequency band. 802.11n is backward compatible with all three previous standards.